x86: Change MMIO addr in readN(addr)/writeN(addr, val) to pointer

On x86, change the type of the address parameter in
read8()/read16/read32()/write8()/write16()/write32() to be a
pointer, instead of unsigned long.

Change-Id: Ic26dd8a72d82828b69be3c04944710681b7bd330
Signed-off-by: Kevin Paul Herbert <kph@meraki.net>
Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Reviewed-on: http://review.coreboot.org/7784
Tested-by: build bot (Jenkins)

src/soc/intel/baytrail/acpi.c

@@ -106,7 +106,7 @@ void acpi_init_gnvs(global_nvs_t *gnvs)
 
 static int acpi_sci_irq(void)
 {
-	const unsigned long actl = ILB_BASE_ADDRESS + ACTL;
+	u32 *actl = (u32 *)(ILB_BASE_ADDRESS + ACTL);
 	int scis;
 	static int sci_irq;